| Filename | /usr/share/perl/5.26/constant.pm | 
| Statements | Executed 62 statements in 1.83ms | 
| Calls | P | F | Exclusive Time | Inclusive Time | Subroutine | 
|---|---|---|---|---|---|
| 1 | 1 | 1 | 248µs | 336µs | constant::BEGIN@4 | 
| 1 | 1 | 1 | 58µs | 70µs | constant::import | 
| 1 | 1 | 1 | 18µs | 18µs | constant::BEGIN@2 | 
| 1 | 1 | 1 | 18µs | 19µs | constant::BEGIN@24 | 
| 1 | 1 | 1 | 8µs | 19µs | constant::BEGIN@90 | 
| 1 | 1 | 1 | 8µs | 21µs | constant::BEGIN@40 | 
| 1 | 1 | 1 | 8µs | 18µs | constant::BEGIN@141 | 
| 1 | 1 | 1 | 8µs | 11µs | constant::BEGIN@3 | 
| 1 | 1 | 1 | 7µs | 18µs | constant::BEGIN@65 | 
| 3 | 3 | 1 | 7µs | 7µs | constant::CORE:qr (opcode) | 
| 1 | 1 | 1 | 5µs | 5µs | constant::CORE:regcomp (opcode) | 
| 1 | 1 | 1 | 3µs | 3µs | constant::CORE:subst (opcode) | 
| 1 | 1 | 1 | 3µs | 3µs | constant::CORE:match (opcode) | 
| 0 | 0 | 0 | 0s | 0s | constant::__ANON__[:174] | 
| 0 | 0 | 0 | 0s | 0s | constant::__ANON__[:190] | 
| 0 | 0 | 0 | 0s | 0s | constant::__ANON__[:192] | 
| 0 | 0 | 0 | 0s | 0s | constant::__ANON__[:41] | 
| 0 | 0 | 0 | 0s | 0s | constant::__ANON__[:42] | 
| 0 | 0 | 0 | 0s | 0s | constant::__ANON__[:43] | 
| Line | State ments | Time on line | Calls | Time in subs | Code | 
|---|---|---|---|---|---|
| 1 | package constant; | ||||
| 2 | 2 | 56µs | 1 | 18µs | # spent 18µs within constant::BEGIN@2 which was called:
#    once (18µs+0s) by Data::Dumper::BEGIN@277 at line 2 # spent    18µs making 1 call to constant::BEGIN@2 | 
| 3 | 2 | 25µs | 2 | 14µs | # spent 11µs (8+3) within constant::BEGIN@3 which was called:
#    once (8µs+3µs) by Data::Dumper::BEGIN@277 at line 3 # spent    11µs making 1 call to constant::BEGIN@3
# spent     3µs making 1 call to strict::import | 
| 4 | 2 | 523µs | 2 | 424µs | # spent 336µs (248+88) within constant::BEGIN@4 which was called:
#    once (248µs+88µs) by Data::Dumper::BEGIN@277 at line 4 # spent   336µs making 1 call to constant::BEGIN@4
# spent    88µs making 1 call to warnings::register::import | 
| 5 | |||||
| 6 | 1 | 600ns | our $VERSION = '1.33'; | ||
| 7 | our %declared; | ||||
| 8 | |||||
| 9 | #======================================================================= | ||||
| 10 | |||||
| 11 | # Some names are evil choices. | ||||
| 12 | 1 | 6µs | my %keywords = map +($_, 1), qw{ BEGIN INIT CHECK END DESTROY AUTOLOAD }; | ||
| 13 | 1 | 2µs | $keywords{UNITCHECK}++ if $] > 5.009; | ||
| 14 | |||||
| 15 | 1 | 5µs | my %forced_into_main = map +($_, 1), | ||
| 16 | qw{ STDIN STDOUT STDERR ARGV ARGVOUT ENV INC SIG }; | ||||
| 17 | |||||
| 18 | 1 | 6µs | my %forbidden = (%keywords, %forced_into_main); | ||
| 19 | |||||
| 20 | 1 | 9µs | 1 | 3µs | my $normal_constant_name = qr/^_?[^\W_0-9]\w*\z/; # spent     3µs making 1 call to constant::CORE:qr | 
| 21 | 1 | 3µs | 1 | 900ns | my $tolerable = qr/^[A-Za-z_]\w*\z/; # spent   900ns making 1 call to constant::CORE:qr | 
| 22 | 1 | 4µs | 1 | 3µs | my $boolean = qr/^[01]?\z/; # spent     3µs making 1 call to constant::CORE:qr | 
| 23 | |||||
| 24 | # spent 19µs (18+1) within constant::BEGIN@24 which was called:
#    once (18µs+1µs) by Data::Dumper::BEGIN@277 at line 45 | ||||
| 25 | # We'd like to do use constant _CAN_PCS => $] > 5.009002 | ||||
| 26 | # but that's a bit tricky before we load the constant module :-) | ||||
| 27 | # By doing this, we save several run time checks for *every* call | ||||
| 28 | # to import. | ||||
| 29 | 1 | 1µs | my $const = $] > 5.009002; | ||
| 30 | 1 | 500ns | my $downgrade = $] < 5.015004; # && $] >= 5.008 | ||
| 31 | 1 | 400ns | my $constarray = exists &_make_const; | ||
| 32 | 1 | 3µs | if ($const) { | ||
| 33 | 1 | 7µs | 1 | 1µs | Internals::SvREADONLY($const, 1);         # spent     1µs making 1 call to Internals::SvREADONLY | 
| 34 | 1 | 2µs | 1 | 300ns | Internals::SvREADONLY($downgrade, 1);         # spent   300ns making 1 call to Internals::SvREADONLY | 
| 35 | 1 | 2µs | $constant::{_CAN_PCS} = \$const; | ||
| 36 | 1 | 300ns | $constant::{_DOWNGRADE} = \$downgrade; | ||
| 37 | 1 | 600ns | $constant::{_CAN_PCS_FOR_ARRAY} = \$constarray; | ||
| 38 | } | ||||
| 39 | else { | ||||
| 40 | 2 | 156µs | 2 | 34µs | # spent 21µs (8+13) within constant::BEGIN@40 which was called:
#    once (8µs+13µs) by Data::Dumper::BEGIN@277 at line 40         # spent    21µs making 1 call to constant::BEGIN@40
        # spent    13µs making 1 call to strict::unimport | 
| 41 | *{"_CAN_PCS"} = sub () {$const}; | ||||
| 42 | *{"_DOWNGRADE"} = sub () { $downgrade }; | ||||
| 43 | *{"_CAN_PCS_FOR_ARRAY"} = sub () { $constarray }; | ||||
| 44 | } | ||||
| 45 | 1 | 87µs | 1 | 19µs | } # spent    19µs making 1 call to constant::BEGIN@24 | 
| 46 | |||||
| 47 | #======================================================================= | ||||
| 48 | # import() - import symbols into user's namespace | ||||
| 49 | # | ||||
| 50 | # What we actually do is define a function in the caller's namespace | ||||
| 51 | # which returns the value. The function we create will normally | ||||
| 52 | # be inlined as a constant, thereby avoiding further sub calling | ||||
| 53 | # overhead. | ||||
| 54 | #======================================================================= | ||||
| 55 | # spent 70µs (58+13) within constant::import which was called:
#    once (58µs+13µs) by Data::Dumper::BEGIN@277 at line 277 of Data/Dumper.pm | ||||
| 56 | 1 | 500ns | my $class = shift; | ||
| 57 | 1 | 600ns | return unless @_; # Ignore 'use constant;' | ||
| 58 | 1 | 200ns | my $constants; | ||
| 59 | 1 | 700ns | my $multiple = ref $_[0]; | ||
| 60 | 1 | 700ns | my $caller = caller; | ||
| 61 | 1 | 300ns | my $flush_mro; | ||
| 62 | my $symtab; | ||||
| 63 | |||||
| 64 | 1 | 400ns | if (_CAN_PCS) { | ||
| 65 | 2 | 167µs | 2 | 28µs | # spent 18µs (7+11) within constant::BEGIN@65 which was called:
#    once (7µs+11µs) by Data::Dumper::BEGIN@277 at line 65         # spent    18µs making 1 call to constant::BEGIN@65
        # spent    11µs making 1 call to strict::unimport | 
| 66 | 1 | 2µs | $symtab = \%{$caller . '::'}; | ||
| 67 | }; | ||||
| 68 | |||||
| 69 | 1 | 400ns | if ( $multiple ) { | ||
| 70 | if (ref $_[0] ne 'HASH') { | ||||
| 71 | require Carp; | ||||
| 72 | Carp::croak("Invalid reference type '".ref(shift)."' not 'HASH'"); | ||||
| 73 | } | ||||
| 74 | $constants = shift; | ||||
| 75 | } else { | ||||
| 76 | 1 | 300ns | unless (defined $_[0]) { | ||
| 77 | require Carp; | ||||
| 78 | Carp::croak("Can't use undef as constant name"); | ||||
| 79 | } | ||||
| 80 | 1 | 1µs | $constants->{+shift} = undef; | ||
| 81 | } | ||||
| 82 | |||||
| 83 | 1 | 1µs | foreach my $name ( keys %$constants ) { | ||
| 84 | 1 | 100ns | my $pkg; | ||
| 85 | 1 | 300ns | my $symtab = $symtab; | ||
| 86 | 1 | 200ns | my $orig_name = $name; | ||
| 87 | 1 | 6µs | 1 | 3µs | if ($name =~ s/(.*)(?:::|')(?=.)//s) {         # spent     3µs making 1 call to constant::CORE:subst | 
| 88 | $pkg = $1; | ||||
| 89 | if (_CAN_PCS && $pkg ne $caller) { | ||||
| 90 | 2 | 237µs | 2 | 29µs | # spent 19µs (8+10) within constant::BEGIN@90 which was called:
#    once (8µs+10µs) by Data::Dumper::BEGIN@277 at line 90                 # spent    19µs making 1 call to constant::BEGIN@90
                # spent    10µs making 1 call to strict::unimport | 
| 91 | $symtab = \%{$pkg . '::'}; | ||||
| 92 | } | ||||
| 93 | } | ||||
| 94 | else { | ||||
| 95 | 1 | 300ns | $pkg = $caller; | ||
| 96 | } | ||||
| 97 | |||||
| 98 | # Normal constant name | ||||
| 99 | 1 | 15µs | 2 | 8µs | if ($name =~ $normal_constant_name and !$forbidden{$name}) {         # spent     5µs making 1 call to constant::CORE:regcomp
        # spent     3µs making 1 call to constant::CORE:match | 
| 100 | # Everything is okay | ||||
| 101 | |||||
| 102 | # Name forced into main, but we're not in main. Fatal. | ||||
| 103 | } elsif ($forced_into_main{$name} and $pkg ne 'main') { | ||||
| 104 | require Carp; | ||||
| 105 | Carp::croak("Constant name '$name' is forced into main::"); | ||||
| 106 | |||||
| 107 | # Starts with double underscore. Fatal. | ||||
| 108 | } elsif ($name =~ /^__/) { | ||||
| 109 | require Carp; | ||||
| 110 | Carp::croak("Constant name '$name' begins with '__'"); | ||||
| 111 | |||||
| 112 | # Maybe the name is tolerable | ||||
| 113 | } elsif ($name =~ $tolerable) { | ||||
| 114 | # Then we'll warn only if you've asked for warnings | ||||
| 115 | if (warnings::enabled()) { | ||||
| 116 | if ($keywords{$name}) { | ||||
| 117 | warnings::warn("Constant name '$name' is a Perl keyword"); | ||||
| 118 | } elsif ($forced_into_main{$name}) { | ||||
| 119 | warnings::warn("Constant name '$name' is " . | ||||
| 120 | "forced into package main::"); | ||||
| 121 | } | ||||
| 122 | } | ||||
| 123 | |||||
| 124 | # Looks like a boolean | ||||
| 125 | # use constant FRED == fred; | ||||
| 126 | } elsif ($name =~ $boolean) { | ||||
| 127 | require Carp; | ||||
| 128 | if (@_) { | ||||
| 129 | Carp::croak("Constant name '$name' is invalid"); | ||||
| 130 | } else { | ||||
| 131 | Carp::croak("Constant name looks like boolean value"); | ||||
| 132 | } | ||||
| 133 | |||||
| 134 | } else { | ||||
| 135 | # Must have bad characters | ||||
| 136 | require Carp; | ||||
| 137 | Carp::croak("Constant name '$name' has invalid characters"); | ||||
| 138 | } | ||||
| 139 | |||||
| 140 | { | ||||
| 141 | 3 | 442µs | 2 | 29µs | # spent 18µs (8+10) within constant::BEGIN@141 which was called:
#    once (8µs+10µs) by Data::Dumper::BEGIN@277 at line 141             # spent    18µs making 1 call to constant::BEGIN@141
            # spent    10µs making 1 call to strict::unimport | 
| 142 | 1 | 1µs | my $full_name = "${pkg}::$name"; | ||
| 143 | 1 | 1µs | $declared{$full_name}++; | ||
| 144 | 1 | 1µs | if ($multiple || @_ == 1) { | ||
| 145 | 1 | 500ns | my $scalar = $multiple ? $constants->{$orig_name} : $_[0]; | ||
| 146 | |||||
| 147 | if (_DOWNGRADE) { # for 5.8 to 5.14 | ||||
| 148 | # Work around perl bug #31991: Sub names (actually glob | ||||
| 149 | # names in general) ignore the UTF8 flag. So we have to | ||||
| 150 | # turn it off to get the "right" symbol table entry. | ||||
| 151 | utf8::is_utf8 $name and utf8::encode $name; | ||||
| 152 | } | ||||
| 153 | |||||
| 154 | # The constant serves to optimise this entire block out on | ||||
| 155 | # 5.8 and earlier. | ||||
| 156 | 1 | 200ns | if (_CAN_PCS) { | ||
| 157 | # Use a reference as a proxy for a constant subroutine. | ||||
| 158 | # If this is not a glob yet, it saves space. If it is | ||||
| 159 | # a glob, we must still create it this way to get the | ||||
| 160 | # right internal flags set, as constants are distinct | ||||
| 161 | # from subroutines created with sub(){...}. | ||||
| 162 | # The check in Perl_ck_rvconst knows that inlinable | ||||
| 163 | # constants from cv_const_sv are read only. So we have to: | ||||
| 164 | 1 | 22µs | 1 | 900ns | Internals::SvREADONLY($scalar, 1);                     # spent   900ns making 1 call to Internals::SvREADONLY | 
| 165 | 1 | 1µs | if (!exists $symtab->{$name}) { | ||
| 166 | 1 | 600ns | $symtab->{$name} = \$scalar; | ||
| 167 | 1 | 1µs | ++$flush_mro->{$pkg}; | ||
| 168 | } | ||||
| 169 | else { | ||||
| 170 | local $constant::{_dummy} = \$scalar; | ||||
| 171 | *$full_name = \&{"_dummy"}; | ||||
| 172 | } | ||||
| 173 | } else { | ||||
| 174 | *$full_name = sub () { $scalar }; | ||||
| 175 | } | ||||
| 176 | } elsif (@_) { | ||||
| 177 | my @list = @_; | ||||
| 178 | if (_CAN_PCS_FOR_ARRAY) { | ||||
| 179 | _make_const($list[$_]) for 0..$#list; | ||||
| 180 | _make_const(@list); | ||||
| 181 | if (!exists $symtab->{$name}) { | ||||
| 182 | $symtab->{$name} = \@list; | ||||
| 183 | $flush_mro->{$pkg}++; | ||||
| 184 | } | ||||
| 185 | else { | ||||
| 186 | local $constant::{_dummy} = \@list; | ||||
| 187 | *$full_name = \&{"_dummy"}; | ||||
| 188 | } | ||||
| 189 | } | ||||
| 190 | else { *$full_name = sub () { @list }; } | ||||
| 191 | } else { | ||||
| 192 | *$full_name = sub () { }; | ||||
| 193 | } | ||||
| 194 | } | ||||
| 195 | } | ||||
| 196 | # Flush the cache exactly once if we make any direct symbol table changes. | ||||
| 197 | 1 | 4µs | if (_CAN_PCS && $flush_mro) { | ||
| 198 | 1 | 7µs | 1 | 1µs | mro::method_changed_in($_) for keys %$flush_mro;         # spent     1µs making 1 call to mro::method_changed_in | 
| 199 | } | ||||
| 200 | } | ||||
| 201 | |||||
| 202 | 1 | 11µs | 1; | ||
| 203 | |||||
| 204 | __END__ | ||||
| # spent 3µs within constant::CORE:match which was called:
#    once (3µs+0s) by constant::import at line 99 | |||||
| sub constant::CORE:qr; # opcode | |||||
| # spent 5µs within constant::CORE:regcomp which was called:
#    once (5µs+0s) by constant::import at line 99 | |||||
| # spent 3µs within constant::CORE:subst which was called:
#    once (3µs+0s) by constant::import at line 87 |